20 G Fishes?

[Delphinus]

[stick in the mud mode: on]

A jawfish, IMHO, will not really take well to a 20g, unless the tank were designed specifically for a jawfish (large open area with deep sandbed). In fact I would say a 20g could be more or less ideal if setup for the jawfish but the average 20g setup, I'd guess no. They are jumpers and would easily jump out of a 20g so a 100% covering would be an absolute must, BTW. So my opinion is forget the jawfish since you said you have others in there.

Ditto the comments on a sixline, 20g might work OK but not really ideal. They can get nasty if there is competition for 'pods, and they can kill competitors. And a 20g doesn't really have a sustainable population of 'pods, so ......

Also ditto on the no for the scooter blenny. Will do fine for a while but will eventually starve. I'd give it about 6 months, 12 on the outside. They just don't last very long to begin with and a 20g won't have enough pods and bugs.

I don't know anything about puffers. I thought they got too big for a 20g but I wouldn't know.

[stick in the mud mode: off]

There are a number of smaller fish who would do well.

A dottyback might work OK (they seem to do well in smaller tanks) however they can be known to be vicious tankmates, so this would have to be a careful choice. I hear good things about the orchid dottyback, Pseudochromis fridmani being less aggressive than other dottybacks. Be careful there is another dottyback, the purple dottyback which looks identical (to me anyhow) but that one is reputed to be nastier.

A fairy wrasse might be OK, although be careful on the species selection because they max out at different sizes (some around 2"-3" which would be ideal, but some grow to 6" which obviously does not belong in a 20g). I have a pair of blueside fairy wrasses (Cirrhilabrus cyanopleura) in my 20g right now. They are doing OK for now but will eventually outgrow this tank. They will max out at around 4". Lubbock's wrasses, C. lubbocki are reasonably frequently available at a very small size (1.5"- 2") and are exquisitely pretty, however, I find are exceedingly shy compared to others (I never see mine, unless he thinks I'm not in the room). And they max out at 6" apparently, so watch out for those.

Cirrhilabrus rubriventralis ( http://www.liveaquaria.com/product/p...fm?pCatId=1158 ) maxes out at 3". That could work well.

I think the flasher/carpenters wrasses (Paracheilinus carpenteri) and filamented flasher wrasses (Paracheilinus filamentosus) may do well in a tank of that size.

Anyhow if you've read up to this point I thank you for not drifting off.